Microbiota of tree roots

It is impossible to know exactly how many trees exist on Earth, although current estimates suggest there are close to three trillion. While this number may seem large, it is only about half of what existed before human civilization, when the planet hosted roughly six trillion trees. Today, we lose around 15 billion trees every year to meet human demands for paper, timber, food production, and agricultural expansion, among others.

The loss of so many trees has profound negative effects on our planet and human well-being. Trees provide a wide range of essential services: they supply valuable products such as timber, firewood, fiber, food (including nuts and fruits), and medicines, while also offering non-commercial benefits such as oxygen production, soil protection, water regulation, carbon sequestration, and the enhancement of recreational environments.

All these benefits—collectively known as “ecosystem services”—largely depend on one vital organ of the tree: the root system and its associated microorganisms. Without these microorganisms, roots could not perform their functions, trees could not survive, and ultimately, neither could we.